A high performance antenna element for wide-angle scan shared-aperture phased array applications

In order to meet the demond on high-performance, compact antenna elements for millimeter-wave high-density wide-angle scan shared-aperture phased array applications, a novelty design approach of broadband shared-aperture antenna element was proposed. A cross-shaped patch is utilized as the radiator of the dual-polarized antenna element operating in Ku-band, and a pair of orthogonal slots are utilized to feed the cross patch so as to produce two orthogonal modes. A probe-fed magneto-electric dipole is utilized as the Ka-band antenna element. Herein, four parasitic small patches are loaded on the top layer to improve the impedance matching and radiation patterns. Meanwhile, the Ka-band element acts as a parasitic loading that surrounds the Ku-band element, which could effectively reduce the resonance frequency of the Ku-band element and simutaneously expand the impedance bandwidth. The simulated results show that the Ku-band element matches well in the frequency range of 14.4–17.6 GHz and 14.4–17.4 GHz for the horizontal and vertical polarization, respectively, with −10 dB fractional impedance bandwidth of 20% and 18.7%. Ka-band antenna works at 30–40 GHz, and has a −10 dB impendance bandwidth of 28.5%. The measured results are in good agreement with the simulated ones. The shared-aperture antenna element is characterized by compact size and wide bandwdith. The transverse size of proposed antenna is 8.5 mm×8.5 mm (0.45λ×0.45λ, where λ is the wavelength at center frequency of Ku band). Therefore, the developed antenna could serve as a novel antenna element for high-density, wide-angle scan shared-aperture phased array applications.